This invention relates generally to a phase-lock system and, more particularly, to a system in which a slave signal is phase-locked to a master signal during a predetermined phase interval of the slave signal.
Phase-lock systems are used in many applications to produce phase coincidence between master and slave signals. One common application is coherent radar in which a reference signal is phase-locked to a transmitted signal and then phase-compared to an echo signal. Other applications involve standby and uninterruptible power supplies, television color control circuits, laboratory measurement and instruction instruments, etc. Typically, phase-lock is accomplished by electronically forcing a slave signal into phase with a master signal. That technique frequently entails a substantial phase-shifting of the slave signal and results in a transient disruption thereof. Such disruptions, even though momentary, can be undesirable under certain circumstances.
The object of the invention, therefore, is to provide an improved phase-lock system.